The objective of this work is to understand further the biochemical events involved in post-transcriptional processing of alpha and beta globin RNA precursors. These precursors will be isolated by mixed globin cDNA-cellulose columns followed by hybridization to globin DNA-cellulose filters specific for alpha or beta RNA sequences. We will then determine the 5'-terminal structure of these RNAs, especially their methylated mucleotides, and the order of their methylation vis-a-vis 3'-end polyadenylation. The rate of synthesis and splicing of individual globin RNA precursors will be assayed and splicing enzyme activities will be measured in erythroid cells at various developmental stages. We will also use alpha and beta cDNA probes specific for intervening sequences of human globin genes to assay thalassemic cells for a defect in RNA processing leading to an excessive accumulation of an RNA precursor. These basic studies are aimed not only at furthering our understanding of the steps involved in RNA processing, but also at discovering a potential regulatory role for these steps in gene expression in eukaryotic organisms.